Proprietary MSR Barrel Nut. WHY!?!??

[Cjive134]

...and I agree. I can't understand why proprietary parts were used. I guess to prevent people from upgrading?

[BC98]

...and I agree. I can't understand why proprietary parts were used. I guess to prevent people from upgrading?

The barrel nut design was likely dictated by the handguard. The majority of aftermarket handguards also use proprietary barrel nuts. I would be very surprised if it's actually a metric wrench size.

Either way, if you can't get it squared away then try to find a local gunsmith who is experienced in AR rifles and see if they can help you.

[Cjive134]

Just an update. I decided to keep the stock barrel, and maybe get a White Oak barrel down the road. Still I wanted to get the barrel nut off.

I got a new plastiXrevolution receiver block set for Christmas, and had a final go at the barrel nut today. I used a pipe wrench, a little heat and it came off without too much force.

Receiver appears to be machined to spec. I didn't see any loc-tite on the threads, but they did NOT grease the threads either which I've always understood to be an important thing. There was grease between the barrel extension and the receiver. No thread damage that I could detect.

I put everything back together. Although I had no way of setting up a torque wrench since the barrel nut is proprietary, 35 to 80 Foot Pounds (Milspec) is a pretty big window to aim for so I feel pretty good about the barrel nut torque.

Knowing what I know now, I would probably have just built another AR15 and been done with it. Overall, I'm still really satisfied with the savage MSR. I'm actually looking at spending the money I saved on the WOA barrel and getting a Savage B22 or Mark II FVSR. Not sure which yet.